Back to Ask the Brewmaster.
This month's question: Why do I need to chill my wort quickly? What types of equipment are available for chilling?
Answer: One of the things that most homebrewers are first taught is that is important to chill your wort quickly. There are several reasons for this:
The bottom line is that you will make better beer with rapidly cooled wort. The simplest method of chilling wort is to put your boiling kettle in the sink at the end of the boil. Fill the sink with water, so that no water gets inside the kettle. One of the double-sided sinks is best, so that you can let the water continue to run and overflow into the empty side and down the drain. Stir the wort with a sterilized spoon to increase the cooling rate. I know of one guy who uses his swimming pool instead of his sink. Another guy in Pennsylvania uses a snowbank.
A more elegant approach is to get an immersion wort chiller. This is a copper coil with fittings that you can hook up to tap water. It fits into the kettle, and provides a considerable amount of surface area for heat transfer. Stirring isn't required with a wort chiller, but is works faster if you do. You need to make sure the chiller is sterile before stuff gets cold. The simplest method is to drop it in the boiling kettle about 10 minutes before the end of the boil. Immersion chillers are simple to use because there is not doubt about if they are clean, and they rarely have any flow problems.
The top-of-the-line cooling method is a counterflow chiller. These are a bit
more complicated, but they make the most efficient use of cooling water. Your
brewing setup will either need to have room below for gravity draining, or else
you need a hot wort pump. Three plumbing connections are needed, with the fourth
typically draining straight into one of your fermenters. The inside coil of
the chiller needs to be sterilized before attaching it to the boiling kettle
spigot. Some people will flush hot wort through to sterilize it, though this
results in a loss of wort. One critical extra thing needed is a strainer on
the inside of the wort spigot to strain out hop leaves, unless you have used
a hop bag. Counterflow chillers are subject to plugging if the strainer gets
plugged, or it is comes loose, letting hop leaves into the coil. This can be
bad news, since you will inevitably risk infecting your wort while you try to
clean it out. If you go with a counterflow chiller, make sure you understand
its workings with a practice run before brew day.
Whatever method you use to cool your wort, you're sure to find that the beer is cleaner tasting and has better clarity, so the extra effort really pays off.